The present invention relates to automatic fastening machines and methods, and, more specifically, to an apparatus and method for automatically drilling and riveting major subassemblies together.
Large objects, such as highway trailers and aircraft wings, typically comprise multiple major subassemblies fastened together. For example, a highway trailer includes major subassemblies such as a roof, side walls, and a bottom frame. The side wall may include bottom side rails that run the length of the trailer and attach to multiple cross beams that connect to the opposing bottom side rails and receive structural support from the bottom frame. During construction, the sides attach to the roof, and a crane then lowers the entire side/roof enclosure to the bottom frame for attachment at the cross beams. In the case of a 60 foot long highway trailer, the load demands and shear size of the major subassemblies require numerous points of attachment to ensure structural stability.
A wide variety of machines exist for attaching one major subassembly to another using bolts or rivets. These machines generally include a first unit to drill holes in the subassemblies, a supply of bolts or rivets, and a second unit to secure the bolts or upset the rivets in the subassemblies. Generally, the machines mount on a platform, and the platform moves relative to the subassemblies to position the machine at a desired attachment location.
In the case of large subassemblies, the rivet locations are often not uniformly spaced. For example, in the manufacture of a highway trailer, as described above, the side/roof enclosure attaches to the bottom side rails which in turn attach to the bottom frame. To increase the structural integrity of the trailer, it is preferable to attach the bottom side rails to the bottom frame coincident with the cross beams. Due to the presence of wheel axles, doorways and other design limitations, however, the cross beams are generally unevenly spaced along the length of the side rails. In addition, manufacturing tolerances result in slight variations in the distance between cross beams on each individual trailer and in the locations of cross beams on other trailers of the same general design and measurement.
The present invention recognizes and addresses disadvantages of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an automated drill and rivet machine to fasten one subassembly to another. The automated drill and rivet machine mounts on a carriage for movement relative to the subassemblies. The machine includes a drill and a masher unit movably mounted on the carriage for drilling holes and mashing rivets. The machine further includes a sensor system for detecting a work site for drilling and communicating this information to a control system. The control system communicates with the carriage, drill unit, masher unit, and sensor system to automatically direct drilling and mashing operations.
It is a further object of the present invention to provide an improved method for fastening components. A machine is provided on a carriage movable relative to the components. The machine includes a drill, a masher, a sensor, and a processor. The machine is indexed to a first work site and placed in a first mode of operation in which the processor repeatedly performs the steps of drilling at a work site, storing the location as a previous work site, sensing a next work site, and moving the drill to the next work site. An operator then inserts a rivet at the previous work site, and at a desired interval, the operator places the machine in a second mode in which the machine repeatedly performs the steps of moving the masher to a previous work site and mashing the rivets at the previous work site.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.